Today, there are numerous situations in which counting how many vehicles are going in which of two directions is useful and important. This can be required in traffic monitoring of a roadways, parking facilities and toll booths. There are two kinds of magnetic sensors that are often used, open loop and magneto-resistive sensors.
The situation has some significant hurdles. Running wires to open loop sensors embedded in roadways turns out to be difficult, expensive, and often unreliable in the rugged environment of a roadway with multiple ton vehicles rolling over everything on a frequent basis. Vehicular sensors employing a wireless communications exchange can be more reliable and less sensitive to the damage of these vehicles and other conditions of these roadways. What is needed is a way to use a report from a wireless vehicular sensor node to count traffic flow on at least one roadway.